1. Field Of Invention
This invention relates generally to a device to reduce the incidence of aspiration into lungs of humans and specifically to an angle measuring device that reminds patient caregivers to elevate an upper torso of a patient at risk for aspiration.
2. Prior Art
Current standards of patient care require that patients at risk for aspiration pneumonia (i.e. pneumonia caused by aspiration of a liquid or solid into the lungs) have their upper torsos elevated at least 30 degrees up to 45 degrees above the local horizontal to prevent or reduce the incidence of aspiration of gastric contents or other liquids or solids into the patient's lungs (hereafter referred to as “aspiration”). This standard could be modified in the future. Examples of patients at risk for aspiration would include: patients on mechanical ventilators, patients with feeding tubes, patients who have had strokes, and any patient with diminished mentation. Treatment studies have shown this degree of elevation significantly reduces the incidence of aspiration pneumonia.
Elevation of the patient is usually accomplished by raising the head of the bed the required 30 to 45 degrees. Various patient care activities (e.g. bathing, changing bed sheets, changing wound dressings, etc.) may require that the patient be restored to a supine position for short periods to perform the required care. In many cases, the restoration of the required 30 to 45 degrees elevation is not accomplished due to some form of distraction to the caregiver. The supine patient remains at increased risk for aspiration, which could lead to pneumonia, respiratory arrest, and even death. This problem could be readily solved by the utilization of some form of a device reminding the caregiver to reposition and maintain the patient at the required 30 to 45 degree upper torso elevation.
Prior art methods of reminding caregivers to maintain the elevation of the patient's torso to reduce the risk of aspiration have been in the form of training programs and posters intended to instill diligence in caregivers. Unfortunately, these methods are not active in nature and rely on the memory of humans to implement.
Prior art methods of utilizing active devices to remind people to perform a function have been very successful. For example, in modern automobiles an audio alarm will sound if a driver of an automobile forgets to remove their keys from the ignition switch after the automobile is turned off and the driver's door is opened. The alarm alerts the driver to remove the keys from the ignition switch to prevent the driver from unintentionally locking the keys in the automobile.
Prior art beds are known to incorporate various angle measuring devices, for example, a goniometer at the joint of a horizontal and elevated portion of a bed. Such devices have not heretofore been known to specifically neither indicate the proper elevation of the torso of the patient at risk for aspiration nor give any indication, passive or active, to the caregiver of the bed being outside of the desired 30 to 45 degree torso elevation to prevent or reduce the incidence of aspiration.
Prior art inclinometers, for example U.S. Pat. No. 559,090 to West (1896), indicate angles directly. This unit is accurate and very inexpensive to construct but fails to utilize a proper scale or indicating device to remind the caregiver to elevate the head of the bed to the specified angular range to reduce the risk of aspiration.
Another example in the prior art is U.S. Pat. No. 5,144,823 to Wood (1992). This pipe bending device utilizes an active aural and visual alarm that indicates to a user when a predetermined angle has been reached while bending a pipe or conduit. This unit utilizes an active, adjustable electrical tilt switch that causes an alarm to sound upon the unit reaching a preset angle and also utilizes a removable attachment fixture to the pipe. This unit fails to utilize the proper scale or indicating device to remind the caregiver to elevate the head of the bed to the specified angular range to reduce the risk of aspiration.
Another example in the prior art is U.S. Pat. No. 6,182,310 to Weismiller, et. al. (2001). This bed side rail incorporates a ball-in-tube inclinometer into the bed side rail. This unit simply indicates the elevation angle of the bed and is visible on only one side of the bed unless two units are incorporated into side rails on either side of the bed. This unit fails to utilize the proper scale or indicating device to remind the caregiver to elevate the head of the bed to the specified angular range to reduce the risk of aspiration.
Prior art goniometers, for example U.S. Pat. No. 6,505,365 B1 to Hanson, et. al. (2003), measure and indicate angles directly. In this instance the goniometer functions as a knee elevation angle indicator. This unit fails to utilize the proper scale or indicating device to remind the caregiver to elevate the head of the bed to the specified angular range to reduce the risk of aspiration.